[Gluster-users] Upgrading ancient gluster version

[Dietmar Putz]

Hi Dave,

based on my experience i would expect problems when old clients trying 
to access a volume with an upgraded gfs.
as mentioned recently i upgraded step by step from 3.4.7 to 3.7.6 and as 
far as i can remember i had problems with a 3.4.7 client when accessing 
a 3.5 volume. because of the geo-replication problem i was under 
pressure and have not been focused no such problems...afterwards i 
upgraded all the clients as recommended before they accessed the volume 
and i never had problems again.

...except this little example :
gluster volume is a 6 node dist.repl. running 14.04 LTS with gfs 
3.7.6...the volume is accessed by some 3.7.6 clients and there is still 
one client with 12.04 LTS and gfs 3.6.7 (3.7 is not available on 14.04 
:( so i have to update the entire node...).
two days ago i tried to set the geo-replication.indexing to off.


[ 21:01:49 ] - root at gluster-ger-ber-08 
/var/lib/misc/glusterfsd/ger-ber-01 $gluster volume set ger-ber-01 
geo-replication.indexing off
volume set: failed: Staging failed on gluster-ger-ber-12-int. Error: One 
or more connected clients cannot support the feature being set. These 
clients need to be upgraded or disconnected before running this command 
again

after disconnecting the client with gfs 3.6.7 (the 3.7.6 clients are 
still connected)  :

[ 21:05:03 ] - root at gluster-ger-ber-08 
/var/lib/misc/glusterfsd/ger-ber-01 $gluster volume set ger-ber-01 
geo-replication.indexing off
volume set: success
[ 21:12:56 ] - root at gluster-ger-ber-08 /var/lib/misc/glusterfsd/ger-ber-01 $

afterwards i was able to connect the 3.6.7 client again.
i don't know all the features being supported by the different gfs 
versions but this example should show that they exist.
a developer could tell you much more about this...

i have to mention that i always followed the 'scheduling a downtime' 
part like in :
http://www.gluster.org/community/documentation/index.php/Upgrade_to_3.5

hope that helps...
best regards
dietmar


On 11.02.2016 23:05, Dave Warren wrote:
> On 2016-02-11 04:27, Dietmar Putz wrote:
>> and i strongly believe you have to update all your clients too.
>> maybe a developer can give you more background information about the 
>> need to do that...
>
> I intend to update all of my clients as soon as possible -- I was more 
> concerned about whether the old clients will cause any problems (to 
> the servers, data integrity, etc) until they're upgraded?
>
> I'd be perfectly willing to block old clients from connecting (and am 
> willing to do so from the firewall if needed)
>

-- 
Dietmar Putz
3Q Medien GmbH
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